A pellet of this type is known from examined German patent application DE-AS No. 21 59 493.
In breathing apparatus, pellets such as pressed tablets of KO.sub.2 are used as a charging material for cartridges that furnish oxygen. It has been shown to be disadvantageous that sufficient oxygen production begins only several minutes after breathing with the equipment starts. For this reason, decomposition catalysts are added to these pellets of KO.sub.2. This causes oxygen production to begin immediately after breathing with the equipment starts, thus bridging the period of inadequate oxygen production at the beginning of breathing with the equipment. However, the catalysts also continue to promote the splitting off of oxygen even after the cartridge has warmed up and oxygen production has already become more than sufficient. In that case more oxygen is furnished by the cartridge than is breathed by the person wearing the equipment. The excess oxygen is vented to the outside via an overpressure valve and so is lost for breathing purposes.
The known pellets having a catalyst are therefore provided merely as a thin partial layer disposed ahead of the charge of an oxygen-furnishing cartridge. In this case, it is a requirement that each cartridge has to contain a fixed amount of two different charges. Having a suitable supply of different kinds of pellets on hand is therefore mandatory.
German Pat. No. 320 810 discloses that a catalyst, for example manganese dioxide, can be dusted in powder form onto a pellet having an alkaline peroxide as the oxygen-yielding chemical after first sufficiently moistening the surface of the pellet by spraying water thereon. However, the application of dry catalyst powder onto the moistened surface of the pellet causes an uneven distribution of the catalyst on this surface. Moreover, the contact of the catalyst with the oxygen-yielding chemical is not complete enough to promote the emission of oxygen in a uniform and intended manner.
It is also known to spray the solution of a catalyst onto a chemical that yields oxygen. In this connection, reference may be made to German Pat. No. 331 721.
Spraying an aqueous solution of manganese sulfate onto sodium peroxide, for example, causes a partial decomposition of sodium peroxide by means of water, producing sodium hydroxide and hydrogen peroxide. The hydrogen peroxide that is formed still sticks to the resulting mixture of sodium peroxide and sodium hydroxide. These additive compounds are then capable of reacting with the applied catalyst.
On the other hand, spraying aqueous solutions of the catalyst onto KO.sub.2 pellets does not improve the reaction performance.